What fraction of Congress is required to override a presidential veto?

To override a presidential veto, a two-thirds majority of both the House of Representatives and the Senate is required. This means that if the president vetoes a bill, Congress must gather sufficient support to reaffirm their approval of the legislation, demonstrating that they believe it is in the best interest of the country despite the president's objections.

The requirement for two-thirds aligns with the framers’ intention to ensure that there is significant legislative consensus before overriding the executive's decision, thereby maintaining a balance of power between the branches of government. This standard reflects a check on executive power while still allowing Congress to assert its authority when there is substantial agreement among its members. In contrast, the other options represent either lower thresholds or unrealistic expectations for override votes that would not adequately reflect the necessary level of consensus.